| Title: | Cold-adapted signal proteins: NMR structures of pheromones from the Antarctic ciliate Euplotes nobilii |
| Author(s): | Placzek WJ; Etezady-Esfarjani T; Herrmann T; Pedrini B; Peti W; Alimenti C; Luporini P; Wuthrich K; |
| Address: | "Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037, USA" |
| DOI: | 10.1080/15216540701258165 |
| ISSN/ISBN: | 1521-6543 (Print) 1521-6543 (Linking) |
| Abstract: | "Cell type-specific signal proteins, known as pheromones, are synthesized by ciliated protozoa in association with their self/nonself mating-type systems, and are utilized to control the vegetative growth and mating stages of their life cycle. In species of the most ubiquitous ciliate, Euplotes, these pheromones form families of structurally homologous molecules, which are constitutively secreted into the extracellular environment, from where they can be isolated in sufficient amounts for chemical characterization. This paper describes the NMR structures of En-1 and En-2, which are members of the cold-adapted pheromone family produced by Euplotes nobilii, a species inhabiting the freezing coastal waters of Antarctica. The structures were determined with the proteins from the natural source, using homonuclear (1)H NMR techniques in combination with automated NOESY peak picking and NOE assignment. En-1 and En-2 have highly homologous global folds, which consist of a central three-alpha-helix bundle with an up-down-up topology and a 3(10)-helical turn near the N-terminus. This fold is stabilized by four disulfide bonds and the helices are connected by bulging loops. Apparent structural specificity resides in the variable C-terminal regions of the pheromones. The NMR structures of En-1 and En-2 provide novel insights into the cold-adaptive modifications that distinguish the E. nobilii pheromone family from the closely related E. raikovi pheromone family isolated from temperate waters" |
| Keywords: | "*Adaptation, Physiological Animals Antarctic Regions *Cold Temperature Euplotes/*chemistry/physiology Models, Molecular Nuclear Magnetic Resonance, Biomolecular/*methods Pheromones/*chemistry;" |
| Notes: | "MedlinePlaczek, William J Etezady-Esfarjani, Touraj Herrmann, Torsten Pedrini, Bill Peti, Wolfgang Alimenti, Claudio Luporini, Pierangelo Wuthrich, Kurt eng Research Support, Non-U.S. Gov't England 2007/08/19 IUBMB Life. 2007 Aug-Sep; 59(8-9):578-85. doi: 10.1080/15216540701258165" |
